The present invention relates to drug delivery apparatus and in particular to neurological drug delivery apparatus comprising a skull mountable percutaneous fluid delivery device.
Implantable drug delivery systems are known for the treatment of neurological conditions where the blood brain barrier prevents many systemically administered drugs from reaching the desired target, or where the delivery of drugs or therapeutic agents to targets other than the desired target may produce unacceptable side affects. In particular, it is known to deliver drugs and other therapeutic agents directly into the brain parenchyma via one or more implanted catheters. Examples of this type of therapy include the infusion of gamma-amino-butyric acid agonists into an epileptic focus or pathway that will block its transmission, the delivery of cytotoxic agents directly into a brain tumour, and the infusion of neurotrophic agents for the protection and repair of failing or damaged nerve cells. The infusion of such neurotrophic agents can be used to treat a variety of neurodegenerative disorders including Parkinson's disease, Alzheimer's disease and Amyotrophic Lateral Sclerosis, and may also be useful in stimulating the repair of damaged neural tissue after injury from trauma, stroke or inflammation.
Fully implantable neurological drug delivery systems have been used for many years. A pump is typically located in the abdomen and tubing is tunnelled subcutaneously to implanted intraparenchymal catheters. Examples of implantable drug delivery pumps for delivery of therapeutic agents to the brain parenchyma are shown, for example, in U.S. Pat. Nos. 4,013,074, 4,692,147, 5,752,930 and WO2004/105839.
It is also known to provide so-called percutaneous access devices that provide a fluid connection between the inside and the outside of the body. Examples of devices that can be used for providing external access to a subject's blood stream are described in US2004/0249361, U.S. Pat. Nos. 6,607,504 and 5,098,397. A stabilised percutaneous access device for neurological applications has also been described previously in WO2008/062173. Transcutaneous fluid transfer apparatus comprising a plate that can be fixed to the skull using bone screws is described in WO97/49438. A percutaneous transferring device that can be screwed to bone is also disclosed in WO99/34754.